Leadership in Energy and Environmental Design certification, distributed antenna systems and public safety radio...
are not often at the forefront of IT executives' agendas and are even less often considered interrelated.
There are, however, solid reasons why IT executives should take a big-picture approach to these subjects and to partner with their employers' real estate or facilities departments to manage them effectively. The goal: to provide better service, cut energy consumption, and ensure access to first responders in the event of fire or other emergency.
Leadership in Energy and Environmental Design (LEED) is a program developed by the U.S. Green Building Council to measure the environmental impact of constructing and operating buildings. There are several levels, from certified to platinum. While there are a lot of factors that go into certification, the key for IT engineers is the standard that governs low-emissivity coating (low-E) for windows. Glass is often insulated with thin coatings containing metal to decrease the amount of energy that can pass through the window. Specifically, the goal of low-E glass is to pass as much visible light as possible while rejecting infrared and ultraviolet wavelengths. But while low-E glass improves a building's energy efficiency rating, thereby gaining the structure LEED points, it has the side effect of decreasing cellular and other radio signals. Moreover, other construction factors -- such as the amount of steel or other metal, and wall thickness and composition -- also affect signal propagation.
Building owners assess alternatives to boost radio reception
Building owners, hopefully in coordination with IT managers, may consider a distributed antenna system (DAS) -- sometimes also referred to as cellular reinforcement -- to improve the performance of cellular service. In a nutshell, DAS rebroadcasts carriers' signals through antennas distributed inside the building.
The selection of DAS technology and vendor can be complicated, however, primarily because the building owners or enterprise is rebroadcasting licensed spectrum that is controlled by service providers. Even IT shops that traditionally run all services in-house should consider partnering with vendors that specialize in DAS installations. Not only is the technology radically different from enterprise IT solutions, but relationships with the carriers, both technically and corporately, also need to be in place in order to rebroadcast licensed spectrum.
Business models constructed around DAS can be complicated. In some cases, the enterprise can deal directly with the manufacturers of DAS systems and the carriers. In this instance, such a deployment is both a capital and an operating expense. This might be difficult for an organization to justify. Ultimately, the building owner or enterprise will be investing resources to improve the service of tenants that themselves are for-profit corporations. For some organizations, this might be an untenable situation.
For others, ensuring that building occupants have good cellular service is either a requirement demanded by users (such as on a college campus) or, in the case of a commercial landlord, seen as a business advantage.
Lack of an enterprise option could cause businesses to solve problems on their own
Without an enterprise solution to address poor cellular performance, users may attempt to resolve problems on their own -- either by deploying consumer-grade solutions such as femtocells -- or potentially worse, by signing individual agreements with multiple providers for cellular reinforcement services.
These types of individual agreements are narrowly focused to address specific problems and may, in fact, contain language that prevents the enterprise from pursuing agreements with other carriers or introducing other cellular reinforcement technologies.
Cellular service isn't the only radio-based communication affected by LEED-optimized construction. Handheld radios (sometimes called land mobile radio service), and used by police, fire and emergency medical personnel, also perform poorly in these buildings. This has become such a problem that the National Fire Protection Association (NFPA) has written sample language to address the in-building performance of 800 MHz radios used by public safety personnel.
This standard details the expected signal coverage and quality for buildings. When adopted by local municipalities, new construction will need to demonstrate proper in-building coverage as part of the inspection, commissioning and occupancy process. This effort to establish building code standards for first-responder radio coverage is happening internationally as well, with the International Fire Code (IFC) Section 510 closely mirroring the NFPA's proposed language.
NFPA72 2010 and IFC Section 510 specify signal strength and coverage areas for public-safety radio service. For example, the latest NFPA standard specifies that public safety radio service must have a signal strength of -95dBm for 90% coverage of the floor area and 99% coverage of critical areas, such as emergency exits, command centers and fire pump rooms. See NFPA72 2010 section 24.5.2 for details.
The good news is that many of the systems that provide the cellular reinforcement demanded by building occupants can also, either as a native function or through add-on modules, provide the proper 800 MHz coverage required by code. Construction managers and IT managers should work together to build a unified system to provide both services. At a minimum, IT executives should include a strategy to address the performance of licensed radio spectrum in areas under their control.
About the author:
Andrew Gallo is a Washington, D.C.-based senior information systems engineer and network architect, responsible for design and implementation of the enterprise network for a large university.
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Andrew Gallo asks:
What steps have you taken to design your network in a LEED environment?
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